Manufacture of petroleum-sulphonic acids and the salts thereof



Patented Mar. 26, 1929.

UNITED STATES PETER IWAINOWITSGH SCHESTAKOFF, F PARIS, ,FRANCE.

MANUFACTURE or PETROLEUM-SULPHONIC Aoms AND THE sAL'rs rnnnnor.

Io Drawing. Application flied February 6, 1926. Serial fl'o. 88,636, and in Germany February 17, 1925,

My invention relates to an improved method of manufacturing petroleum sulphonic acid and the salts thereof.

In the known process of refining petroleum distillates with the aid of concentrated sulphuric acid alone or mixed With sul huric acid anhydride sulphonic acids are ormed which mainly remain in the solution of hydrocarbons whilst only a minute portion thereof goes into the sediment consisting of acid tar. from the distillate the sulphonic acids separate from the latter in the form of alkali salts or as free acids. In the former case it is customary to treat the distillate with an aqueous or alcoholic solution of alkalis, whereas in the latter case an aqueous solution of alcohol or acetone is employed for the purpose of recovering the sulphonic acids from the distillate. In either case and particularly if heavy distillates are under treat- ,ment, the sulphonic acids and the salts thereof obtained in this way, will have a considerable percentage of hydrocarbon oils so that they are of little use or even useless in certain domains of industry e. g. for washing textile fabrics and the like.

I have discovered, after much study and research, that I can separate the sulphonic acids, in a ready and efficacious manner, from petroleum oil and from other hydrocarbon oils by means of acetic acid esters which are soluble in water such as e. g. methylic alcohol or glycerine, which are soluble in petroleum sulphonic acids and at the same time capable of promoting the separation of the hydrocarbons there rom. In lieu of the stated acetic acid esters, acetic acid may, however, be used .just as well which is the equivalent thereof.

I have found that in this manner highly satisfactory results will be obtained not only in case of separating the sulphonic acids from petroleum hydrocarbons, but also in the case of purification of hydrocarbon oils the alkali salts of which are produced in the process of treating sulphonated distillates with alkalis, and furthermore in the case of separating the oils from aqueous solutions of the sul honic acids which are obtained by washing 1; e said distillates with water. In the case of dilution by means ofwatersoluble acetic acid esters at a raised tempera- Upon separation of the acid resin -tion of caustic soda.

ture, the hydrocarbon oil absorbed by the same W111 form a top layer and may be readily separated from the bulk. The acetic acidesters may be removed by way of evaporation, from the sulphonic acids or the salts thereof freed from oil.

Example 1.A distillate of the spindle oil produced from Baku petroleum and having a specific gravity of 0,9 is treated at a temperature of 70 to 80 C. first with concentrated sulphuric acid and subsequently with a mixture of concentrated sulphuric acid and sulphuric acid anhydride in a proportion of 5 tol. The mixture is allowed to stand and uponthe removal of the acid tarry sediment, the oil layer is mixed with three percent of a 7 5 percent methylie aceticester. On heating the mixture at a moderate temperature the sulphonic acids will deposit at the bottom in the form of a thick mass.

Err-ample 2.-A distillate of solar oil having a specific gravity of from 0,875 to 0,885 is "5 treated with a mixture of eight parts of concentrated sulphuric acid and two parts of sulphuric acid anhydride and subsequently neutralized by means of a two percent solu- The mixture is allowed to stand and the layer, containing the alkali salts of the sulphonic acids, formed thereby is separated and treated with 10 to, 15 parts of sodium chloride. The sulphonates thus separated by means of the salt are mixed with 15 percent of methylic acetic ester acetic acid and the mixture is heated up to a temperature of 50 CL, whereby the-mineral oil contained in the salts will be separated so as to form a top layer. I have found that in case of raising the pressure the oil will separate more completely with greater speed.

The methylic acetic ester is separated from the sulphonic salts freed from mineral oil,

by distillation and the thus recovered acetic\ acid may be used anew for the like purposes. The sulphonic acids and the salts thereof produced according to the method described above, are used in the trade for s )littin up fats, manufacturing certain specific was ing preparations and in the manufacture of textile fabrics.

Although I have described specifically only two ways of carrying out my invention, it is to be understood that various changes and modifications may be made therein without departing from the spirit of my invention'and the spirit and scope of the appended claims.

What I claim is: v

1. A method of isolating oil-soluble sulphonic acids which comprises treating a sulphonated petroleum oil with a water-soluble ester of acetic acid to separate the sulpho compounds. 1

2. A method of isolating oil-soluble sulphonic acids which comprises treating a sulphonated petroleum oil with water to obtain a solution of sulphonic acids and treating the latter with a water-soluble ester 0 acetic acid.

In testimony whereof I affix my signature.

PETER IWANOWITSCI-l SQIESTAlOl-l'. 

